Muffler



Aug. 29, 1933.v L, L. HAAs Er AL MUFFLER Filed Ooi. '7, 1930 PatentedAug. 29, 1933 UNITED sTATEs PATENT OFFICE MUFFLER poration of New YorkApplication October 7, 1930. Serial No. 486,937

7 Claims.

This invention relates to improvements in mufilers of the kind commonlyemployed in connection with internal combustion engines for reducing thenoises caused by the exhaust of the engines.

The objects of this invention are to provide a muffler of improved andsimpliiied construction, in which a straight, uninterrupted passagethrough the muler is provided, and in which bailles or deilectors areprovided which cause portions of the gases to impinge upon otherportions of the gases to reduce the noises of the exhaust; also toprovide a muler in which bailles are employed, which are arranged tooperate by an ejector action to cause a portion of the gases flowingthrough one part of a baille to induce a flow of another portion of thegases through another part of the baiile, and then mixing these twoportions of the gases, thus breaking up the sound Waves to produce asilencing effect; also to provide bailles of this type With deflectorsof improved construction which assist in guiding the two portions of thegases into contact; also to provide a muiller of this kind, in which abaille may have other parts secured thereto to form a unit, which inturn is secured to the shell of the muffler; also to improve theconstruction of muiilers in other respects hereinafter specified. v

In the accompanying drawing:

Fig. l is acentral longitudinal section of a muler embodying thisinvention;

' Fig. 2 is a transverse sectional elevation thereof, on line 2 2, Fig.1.

In the muiller illustrated in the drawing, and which constitutesoneembodiment of our invention, A represents the outer cylindrical shell ofthe muiiler which is provided at one end with a head B suitably securedto the shell and having a short cylindrical projection b, which may beconnected with the exhaust pipe of an engine and through which the gasesenter the muiller. At the other end of the shell a discharge head C isprovided, secured at its outer portion to the shell, 45 and having atubular projection c, which may be connected to a tail or discharge pipe(not shown),

or .through which the gases may be discharged directly to theatmosphere. All of these parts,

which constitute the housing of the muiller, may

,-0 be of any suitable or desired construction and of themselves form nopart of'this invention.

D represents bailles embodying this invention, three of these balesbeing shown in the construction illustrated,v but it will be obviousthat any desired number may be employed in a muffler to produce thedesired muilling effect. Each of these bailles is preferably providedwith an outer flange 5, which may be welded or otherwise secured to fthe inner surface of the shell A of the muffler. 60 The baille isofsubstantially funnel shape, tapering more or less irregularly in thedirection of the flow of gases through the muffler. The baille has asubstantially central discharge opening or orillce 6 therein, which ispreferably in the form of a short tube formed integral with the baille.The portion of the baille between the outer ange 5 and the dischargepassage 6 may be more or less tapered or stepped toward the direction offlow of the gases, an intermediate inclined portion 7, in the particularconstruction shown, being provided with a series of apertures oropenings 8 therein, through which some of the gases passing through themulller may flow. By means of this construction, there is a tendency ofgases to iiow both through the orifice 6 and through the severalapertures 8 arranged about this central opening. The flow of gasesthrough the aperture 6 has an ejector action, forming a partial vacuumat the side of the baffle facing the discharge end of the muiiler. Thisaction of the gases passing through the central aperture 6 induces aflow of gases through the apertures 8 in addition to the amount of ilowthat would pass through these openings without the ejector`action. Thegases passing through these apertures are then mixed with the gaseswhich have passed through the opening 6. This mixing of the gasesresulting from the ejector action, together with the impinging of thegases discharged through the openings 8 against the jet of gas from theorice 6, produces an effective reduction of the noises of the exhaust bybreaking up of sound waves.

At the left hand side of Fig. 1, a second baille E is provided which issimilar in construction to the baille D, except that the baille E isprovided at its outer edge portion with a tubularv extension 10 whichmakes it possible to secure this baiile to a cylindrical portion orshoulder 9 of the baille D adjacent to the flange 5 but of lesserdiameter than the flange 5. This baille E, acting on the gases in amanner similar to the baille D and in conjunction with the baffle D,produces a greater silencing effect than the baffle D alone. By means ofthe construction described, the baffle E can be welded or otherwisesecured to the baille D before the baille D is secured to the shell A,thus facilitating the assembling of the two baffles in the muiller.

If desired, the ejector action of the baffles may be supplemented byproviding means for guiding gases discharged through the openings 8 inthe bailles toward the jet of gas discharged through the orice 6. Anydesired construction may be employed for this purpose, that illustratedin the drawing including a deilector F, which may be used in connectionwith the bailles D or E as shown in Fig. 1. This deflector issubstantially bell or funnel shaped, the edges thereof being secured tothe shoulder 9 of the baille D, or if a deflector of this type is to beused in connection with the baille E, it may, if desired, be secured toa shoulder 11 formed on the baille E, as illustrated at the left ofFig. 1. The deflector F is provided with a discharge passage or opening12 which is preferably of somewhat greater diameter than the dischargepassage 6 in the baille D, or of the discharge passage 10a in the bailleE. The concave curved or bellshaped portion 14 of the deflector is soshaped as to guide any gases discharged through the apertures 8 in thebaille D, or through the corresponding apertures in the bailleE, towardthe axis of the muiiler. Thus, the deflector F ensures a positivemovement of the gases discharged through the apertures 8 toward the axisof the jet of gas discharged through the orifice of the adjacent baille,and thus causes them to impinge against gases discharged through thepassage 6 and also assists in causing a mixing of the gases, thus addingma terially to the silencing effect produced by the baille alone.

In the muiller illustrated, three different arrangements of bailles areillustrated, and muillers may be built using any one of the threearrangements shown, or using any combinations of. these arrangements.The deflectors F have been found very desirable and of great value inhelping to silence noises of the exhaust, but it will be understood thatit is not necessary to use these deflectors, since satisfactory muillingeffects can under certain conditions be produced by merely using bafflesalone. Different arrangements of the bailles, and deflectors shown, andany desired number of baffles and deflectors per muiller may also beemployed in constructing muillers for different sizesof engines toproduce the desired silencing eilect on different volumes of gasesdischarged by different engines.

By spacing the bailles or bailling units at distances from each other inthe shell of the muffler, expansion chambers are formed between thebaffles or units in Which lthe gases are permitted to expand. Thisalternate arrangement of baflles and expansion chambers `also assistsin'silencing noises.

The muiller described is thoroughly effective in operation of sturdyconstruction, and is also easily manufactured.` The baflles anddeflectors can be formed by stamping operations and the assembling ofthe bailles and deflectors into units can be easily done by spot weldingor other means, before the units are assembled in a shell, andconsequently, the correct positioning of the parts of the unitsrelatively to each other is greatly facilitated. The units or individualbailles, if such are used, can then be very easily secured by welding orotherwise in the single shell of the muiller.

We claim as our invention:

1. A muffler having a housing provided with inlet and dischargeopenings, a baille arranged in said housing and having a dischargeorifice approximately equal in size to the discharge opening in saidhousing and openings of smaller size arranged about said oriiice, and adeflector arranged within said housing beyond said baffle and `having anopening in alinement with said oriflee and imperforate walls formed toguide gases flowing through said openings in said baille tovarrangedabout said orifice, and a deflector mounted on said baille and having adischarge opening larger than said orifice and in alinement therewithand having an imperforate Wall for guiding gas discharged from saidopenings of said baille toward the jet of gas passing through saidorifice.

3. A muiller having a housing provided with inlet and dischargeopenings, a baille arranged in said said housing and having a dischargeorifice approximately equal in size to the discharge opening in saidhousing and openings of smaller size arranged about said orifice, and adeilector secured on said baille having a concave portion formed toguide gas discharged from said openings toward the jet of gas dischargedthrough said orifice and having an opening in alinement with saidorifice of said baille, said deflector being otherwise imperforate.

4. A muiller including a substantially cylindrical housing, asubstantially funnel-shaped baille secured to said housing within thesame and which tapers in the direction of flow of the gases through saidmuiller, and which has an orifice in the smaller end thereof andopenings arranged about said orifice, and a deflector supported entirelyfrom said baille and having a curved portion which guides gasesdischarged through said openings radially toward the jet of gasdischarged through said orifice.

5. A muiller having an outer shell and having inlet and dischargeopenings, a substantially funnel-shaped baille arranged within saidshell and tapering in the direction of flow of gases through saidmuffler, the outer portion of.said baille being secured to the shell ofthe muiiler, said baille having a discharge orifice in the smaller endthereof approximately equal to the discharge opening of the muiller, andopenings of smaller size arranged about said orifice, and a`deflectorsupported entirely on said baille and having walls which curve inwardlytoward the axis of the orifice of said baille to guide gases dischargedthrough said openings towards the sides of the jet of gas dischargedthrough said orifice.

6. A mufller having an outer shell, a baille arranged in `said shell andhaving a flanged peripheral portion secured to said shell, said bailletapering in the direction of flow of gases through the muffler 'andbeing provided with a substantially central discharge orifice, asubstantially cylindrical shoulder portion formed on said baille and ofless diameter than said flange, and discharge openings in said baillearranged between said orifice and said shoulder, and gas deflectingmeans secured to said shoulder for deflecting gas discharged throughsaid openings toward the jet of gas discharged through said orifice.

7. A muffler having an outer shell, a baille arranged in said shell andhaving a flanged peripheral portion secured to said shell, said bailletapering in the direction of flow of gases through the muiller and beingprovided with a substantially central discharge orifice, a substantiallycylindrical shoulder portion formed on said baille and of less diameterthan said flange, and discharge openings in said baille arranged betweensaid orifice and said shoulder, and a substantially bell-shapeddefiector having a central opening and having its portion of greatestdiameter secured to said shoulder for deflecting gases dischargedthrough said openings toward the :let of gas discharged through saidorifice.

LUCIEN L. HAAS. GAIL C. STARKWEA'IHER.A

